A digital micromirror device (DMD) is a type of micro electromechanical system (MEMS), wherein a large number of micromirrors are arranged in an array. Each micromirror in the DMD can pivot on a hinge about an axis to reflect light produced by a light source either away from or onto a display plane, based on image data. Light reflected away from the display plane corresponds to a dark region of an image, while light reflected onto the display plane corresponds to a light region of the image. A combination of light reflected by the micromirrors in the DMD produces an image on the display plane, with color being provided by a multi-color light source or the use of color filters.
The position of a micromirror can be determined by the state of a memory cell fabricated underneath the micromirror. If the memory cell is in a first state, the micromirror can pivot to a first position and if the memory cell is in a second state, the micromirror can pivot to a second position. Electrostatic forces are used to change the position of the micromirror from one position another. However, since each micromirror has a mass, sufficient energy must be provided to each micromirror to overcome any stiction (static friction) that will tend to keep the micromirror in its current position. The energy is also needed to overcome hinge memory that will preclude a successful position change. However, if too much energy is provided to move the micromirror, the micromirror may be accelerated to such a high velocity that permanent damage can occur to the micromirror and/or a micromirror landing site. Damage to the micromirror landing site can cause increased stiction, requiring greater energy to ensure the positive movement of the micromirror.
With reference to FIG. 1, there is shown a diagram illustrating portion of a DMD 100 showing a mechanical energy storing structure used in a DMD to provide energy to help ensure the positive movement of a micromirror. The mechanical energy storing structure in the DMD includes a flexible member 105 that can be attached to an immovable structure 110. The flexible member 105 can deflect in a downward direction when a micromirror 115 lands on the flexible member 105, storing mechanical energy that can be released to help assist the micromirror 115 pivot to a different position. The flexible member 105 can be fabricated from a metallic material, such as aluminum or an alloy of aluminum. The flexible member 105 can be attached to the immovable structure 110 or the flexible member 105 may be a formed from the immovable structure 110. The deflection of the flexible member 105 also helps to decelerate the micromirror 115 and reduce the deceleration impulse on the micromirror 115, which can help to mitigate damage to the micromirror 115 or a micromirror landing site.